View Full Version : LS1 fuel system questions

01-28-2005, 10:52 PM
I'm quite new to this EFI thing so take it easy on me :scared:

I'm trying to plan out a possible fuel system for my 81z/LQ4 conversion.
If I go the aeromotive external pump/reg route and sump my stock tank, can I use the factory 81 pickup? Would the return still go to the top of the tank to the pickup? Why do most sumps have 2 bungs? I know one is supply but what is the other for if not for a return? Will I still need a baffle for the external pump?

I appreciate any help :worship:

01-29-2005, 04:52 AM
Your stock pickup is from the top of the tank, so I don't know what you mean by that if you are also running a sump. If you want to use that as the return line, then yes, that will work. Most sumps have dual bungs to support nitrous oxide ... n2o requires additional fuel, and some systems have a second fuel pump to be used when the n20 is being injected. Using a sump usually means that the original tank skin can function as baffling. Don't cut out the whole tank area where the sump goes, just drill a couple of 1" holes. Weld the sump on, and you're baffled.

Good luck.


01-29-2005, 03:15 PM
Hey Mike, check this out, I found it in another thread:


01-29-2005, 06:07 PM
John - What I meant by using the stock pick up was to use it for the fuel guage and retur only. I would then use one of the bungs in the sump for the supply. Your baffle answer is just what I was looking for if choose the external pump layout.

Ryan - I've seen the Tanks Inc setup and it looks pretty good. I also talked to North Road Radiators and they can graft in the pump and baffle area from a steel 98 tank into my stock 81 tank for a few hundred bucks. I may go that route instead.